1. Field of the Invention
The present invention relates to disk drives for computer systems. More particularly, the present invention relates to a disk drive comprising control circuitry powered by a secondary voltage supplied by a center tap of a spindle motor during a normal operating mode.
2. Description of the Prior Art
Disk drives typically employ a multi-phase spindle motor (e.g., a three phase spindle motor) for spinning a disk while a head writes data to and reads data from the disk. The head is connected to a distal end of an actuator arm which is rotated about a pivot by a voice coil motor (VCM) in order to actuate the head radially over the disk to access radially spaced, concentric tracks. The disk drive receives power from a host computer, including a 12V supply for powering the spindle motor and VCM, and a 5V supply for powering the control circuitry for controlling the operation of the disk drive. Requiring the host computer to provide two supply. voltages can increase the cost of the host computer in certain applications, such as mobile devices, set top boxes, game systems, etc., which may operate on a single supply voltage.
There is, therefore, a need to reduce the cost of supplying two supply voltages to a disk drive while maintaining adequate spindle motor and VCM performance.